Effect of Low Substrate Temperature on the Magnetic Properties and Domain Structure of Fe₇₀Ga₃₀ Thin Films

We report on the effect of low substrate temperature on the correlation between structure, magnetic properties, and micromagnetic behavior of Fe₇₀Ga₃₀ thin films. The enhanced grain size and the decrease in the number of pinning centers are in correlation with the enhanced saturation magnetization and domain size (~0.2-0.5 μm), respectively. Estimated effective magnetic anisotropy energy (K_eff) is found to increase with substrate temperature from 7.5 × 10⁵ J/m³ (room temperature) to 13.6 × 10⁵ J/m³ (350 °C). The coercivity variation from the object-oriented micromagnetic framework (OOMMF) simulation is in line with respect to experimental values. Spin structure from simulation also indicates multiple-domain configuration when there is a magnetization reversal.